Short chain ring bolts from where and what ratio for a roadie SS?

Have retro (rusty & scratched) old road bike frame and most of the bits to build myself a fakenger.
So where can I get shorted chain raing bolts and what ratio for a fat biffer on slightly undulating terrain?
Ta

i've used dropout bolts for my single ring and they're working fine, i've been riding ss road for a 3 months now and 48 - 17 is doing me pretty well in bournemouth dorset and the surrounding area. some of the fakengers i know (me included) are running various different set ups though but usually around the 48 - 16/17/18 mark, though one guy is running 53 - 16 i think...
calves of steeeel!